Konica Hexar 2.8/90 soft wide open

[retow]

There are many positive comments about the Konica Hexar 90/f2.8 in this forum and others, comparing it performance wise with the Elmarit M 90mm. Because of its compact size and light weight, I decided to try one and use it as my travel 90, which potentially could replace the ME 90, which is excellent but often I felt that a faster lens would be great.

Build quality of the Hex is top. However, fully open it is quite soft on my M8. At f4 it renders reasonably sharp, to be at its best starting at f5.6. Comparing it with the 90AA and the 90 Macro Elmar, I´m somewhat disappointed.
How does this compare with your experience with the KH 90?

 

[Krosya]

I have one and it is very sharp wide open on my Film cameras - Hexar RF and Leica M6. Never tried in on a digital since I don't have one with M mount. See this thread for some examples : http://www.rangefinderforum.com/forums/showthread.php?t=50209

PS Shouldn't this be in Hexar RF section? 😉

 

[Dante_Stella]

It's not soft; the focus needs to be adjusted for the M8. Properly adjusted, the lens will easily overmatch the M8 sensor, even wide open.

 

[akptc]

I'd agree that's it is not soft at all wide open. Presumably needs some adjustment.

 

[retow]

It's not soft; the focus needs to be adjusted for the M8. Properly adjusted, the lens will easily overmatch the M8 sensor, even wide open.[/


Dante

Thank you for your input. Would you have any suggestion who could do the adjustment in the US.

retow

 

[awilder]

I would send the lens and body to DAG camera repair. The camera's RF may be slightly off or the lens rf cam might need adjustment. Don can determine which is off and easily fix it but unless you give him a reasonable date you need the camera back, expect at least a 5-6 week turnaround.

 

[Dante_Stella]

DAG can do it. It's not expensive, but it may take a while.

By the way, the focal plane offsets as measured when I had various lenses redone by DAG and others were (all lenses were focusing slightly behind the subject):

28mm M-Hexanon - 0.04mm

50mm M-Hexanon - ~0.02mm (I suspect this was 2/1000 of an inch, or 0.05mm, but I don't remember/was not listening carefully enough)

90mm M-Hexanon - 0.05mm

21-35mm M-Hexanon - didn't get that figure. But the end result was just about sharpest lens I have ever seen.

These are "as-built" figures - and as built, all of these lenses interchanged handily with a Hexar RF and M3 (thank you wider tolerances with film!). But an M8, which has much, much tighter tolerances and a dead-flat imager, wants some adjustments.

If you have the lenses adjusted, you should consider having your Hexar RF's flange to focal plane distance reduced so that things do not end up out of tolerance (note: focus accuracy will suffer very slightly in rapid-fire shooting because the film does not bulge into position immediately). DAG does not charge very much for that (and it was 0.05mm circa). I think it was under $50. I have not been able to detect any focus error with body and lens so modified. We're good for eyelashes at 90mm, f/2.8 and a meter.

Do note that DAG is a bit reticent with Loctite, which Konica used in abundance in locking stuff down. Some lenses are tougher than others. He very recently worked on my 50mm and 90mm, so he should be familiar (or at least remember) how things work.

Bon chance!
Dante

It's not soft; the focus needs to be adjusted for the M8. Properly adjusted, the lens will easily overmatch the M8 sensor, even wide open.[/


Dante

Thank you for your input. Would you have any suggestion who could do the adjustment in the US.

retow

 

[Cron]

ok, all seems to be said;
mine works perfectly wide open together with my M6 0,85-finder and I sold my Elmarit seeing the results of the Hex 90